This study revisits the existing scholarly debate on the possible impact of the principal's leadership on student achievement. Both `direct effect' and `indirect effect' models are discussed. A quantitative meta-analysis examines to what extent principals directly affect student outcomes. The small positive effects found in this meta-analysis confirm earlier research findings on the limitations of the direct effects approach to linking leadership with student achievement. Finally, lines of future research inquiry are discussed.

In the past 3 decades, the concept of professional community has gained considerable momentum in the theoretical and empirical studies in this field. At the same time, the concept has faced conceptual and methodological difficulties in that as yet no universal definition has been formulated and that its operationalization differs in the various empirical studies conducted on the subject. This study presents a comprehensive synthesis of the theories currently available and their implications for the conceptualization and operationalization of the professional community concept including a meta-analysis of the studies that investigated the effect of professional community on student achievement. Our meta-analysis reported a small but significant summary effect (d = .25, p < .05), indicating that within a school environment professional community could enhance student achievement. Furthermore, the need for the conceptual and empirical validation of the concept's key dimension was discussed.

Purpose: This meta-analytic study examined associations between minority stressors and suicidal ideation and suicide attempts among LGBT adolescents and young adults (aged 12–25 years). Methods: Identified studies were screened using the inclusion and exclusion criteria. Studies had to include an association between a minority stressor and a suicidality outcome and were categorized into 10 meta-analyses. Overall effect sizes were calculated using three-level meta-analyses. In addition, moderation by sampling strategy was examined. Results: A total of 44 studies were included. Overall, LGBT bias-based victimization, general victimization, bullying, and negative family treatment were significantly associated with suicidal ideation and/or suicide attempts. Associations of discrimination and internalized homophobia and transphobia with suicidal ideation and/or suicide attempts were not significant. No moderation effects were found for sampling strategy. Conclusion: Although overall effect sizes were small, our meta-analytic study shows a clear link between various types of minority stressors and suicidal ideation and suicide attempts among LGBT adolescents and young adults.